You can request platforms via the support hub: https://www.speedrun.com/knowledgebase/supporthub/request-platform

Famicom is on the site https://www.speedrun.com/games#platform=FDS

edit: im not a console expert apparently famicom is not fds for the 2DS you'll have to request the platform

Merl, I think he means the japanese version of the NES. The FDS is an disk addon for the Famicom. I assume that's what OP is talking about.

Famicom and Super Famicom aren't added because they are just the japanese counterparts of the NES and SNES, so they are pretty much the same.

And 2DS is for all intents and purposes the exact same as 3DS.

@Merl_ Kosmic did an explanation of the FDS vs Famicom pretty recently. It's amusing:

2DS and New 2DS are just the same platform as the 3ds without the 3d scroll bar (which no one uses) and a flip screen. So there's no need to add them as their own platforms.